Control mechanism for oven burners



C. M. MAYER ET AL CONTROL MECHANISM FOR OVEN BURNERS 3 Sheets-Sheet l M222 JOKPZGH 2.52

NJQQDUOSGMIP April 21, 1953 Filed Dec.

April 21, 1953 c, M. MAYER ET AL 2,635,632

CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 11, 195o s sheets-sheet 2 INVENTORS 4 '/70 Nes' M /Vcz yer By 9J@ /IH M Hoff April 21, 1953 c. M. MAYER ET AL 2,635,632

I CONTROL MECHANISM FOR OVEN BURNERS Filed Dec. 11, 1950 5 Sheets-SheerI 5 Patented Apr. 21, 1953 UNITED STATES PATENT GFFICE CONTROLMECHANISM FOR OVEN BURNERS Charles M. Mayer and John M. Hoi, Mansfield, Ohio, assignors to The Tappan Stove Company, Mansfield, Ohio, a corporation of Ohio Application December 11, 1950, Serial No. 200,201

burner which must burn constantly all of the time the Amain burner is turned on. The pilot burner is ignited by an electrical resistance ignition element which is automatically deg-energized after the pilot burner has been ignited.

In most cooking ranges in use today it is immaterial whether or not the oven burner burns constantly as long as the pilot burner associated therewith is ignited. It may be extinguished for some reason but it will be promptly reignited by the pilot burner if fuel is supplied thereto. But if the pilot burner is extinguished for any reason while the main control valve is still open to supply gas to the main burner a very dangerous situation sometimesarises. Let us assume that both the pilot burner and the main burner are extinguished during .operation for some reason. Gas can then flow to the main burner but since the pilot burner is extinguished thermain burner Will not be ignited and unburned gas will accumulate in the oven which may violently explode when an attempt is made to ignite either the main or pilot burner.V It has been found by experiencev that both the pilot burner and the main burner are. frequently extinguished during userwhile the main` control valve is open to supply gas to the main'burner.` This is sometimes due to a momentary failure `of the gas supply or the slamming ofthe oven door or to various other reasons.

In order to prevent an accumulation of unburned gas and thus eliminate danger of an explosion therefrom in the event the pilot burner is extinguished for any reason while the control valve is still open to supply gas to the main burner, we provide our improved safety control valve mechanism by which the supply of gas to the main burner is cutoff independently of the main control valve, in the event'the pilot burner is extinguished for any reason while the main gas control valve is open. We lhave shown our'improved valve mechanism incorporated in anY automatic ignition and control system which includes a main gaseous fuel burner by vwhich the oven in a cooking range is heated. kThe main,V burner is adapted to be ignited by a gaseous fuel pilot burner which burns only during the 'time the oven is in operation. -At other-times'the Vsupply of gas to both 7 cnimsyror 137-576) the main burner and the pilot burner is c ut off by a main control valve which is interposed in a conduit between the gas supply manifold and the burners. When the main control valve is open gas will flow from the main control valve and into our improved safety control valve mechanism. From the safety control valve mechanism gas will flow through a small branch conduit directly tothe pilot burner; and through the main conduit and a standard thermostatically operated oven temperature control valve to the main burner. A normally open master control switch which is operatively associated with the main control valve is arranged to be closed by the opening of the main vcontrol valve Vand to be opened by .the closing of the main control valve. The closing of the master control switch, as the main control valve is opened to supply gas to the burners, energizes through a normally closed thermostatically, operated switch ,an electric resistancedignition element and a solenoid which is operatively connected to the safety control valve mechanism. Therenergization of the solenoid causes it tov operate `rthe safety control valve mechanismto permit the flow of gas to the pilot burner while cutting oif the supply Vof gas to the main burner. The pilot burner is then ignited by the electric ignition element. and projects a flame against a thermostatic element, which Acontrols the operation. of the normally closed switch, and jagainst'a thermocouple which is in circuit with an electromagnet in the safety control valve mechanism. After the thermostatic element becomes heated it opens the normally closed switch which de-energizes the electric ignition element and the solenoid. As soon as the solenoidy is de-energized the safety control mechanism is y,automatically operated by spring means toY supply gas to the main burner through the oven temperature control valve. The

main burner is then'ignited by the pilot burner.V

The thermocouple, as long as it is heated by the pilot burner, maintains the safety control valve mechanism throughthe electromagnet in condition to supply gas to both the main burner and the pilotl burner. I The oven temperature control valve lthen regulates the supply of gas to the-main burner so as to maintain the desired oven temperature. As long as the pilot burner is ignited thejmain 'burner will burn normally under the control ofthe oven'temperature control valve until the maincontrolvalve is manually turned ofi. ',But ifY during operatonfthe pilot burner is extinguished for any reasonpthe thermocouple will immediately cool and cause the safety control valve mechanism to automatically cut off the supply of gasto both ,they

mainV vburner y and *ther pilot burner. j As an; vexamplevof thefdmannerzoffoperation of the apparatus, letus 'assume' that .duringV operation' the pilot burner is suddenly extinguished, for instance, by a momentary failure of the gas supply from the manifold to the burners. The thermocouple immediately cools, causing the safety control Valve mechanism to cut off communication between the manifold and both the main burner and the pilot burner. The main control valve is still open and the master switch closed. Then after the thermostatic element has cooled, closing the normally closed switch, which is maintained open by the thermostatic element during normal operation of the oven, the electric ignition element and the solenoid are again energized. The energization of the solenoid will cause it to operate the safety control valve mechanism to re-establish communication between the manifold and the pilot burner only. Then when gas is again available the pilot burner will be ignited and reestablish normal operation of the oven as previously described. In' the event ofay power failure during normal operation of the oven, the main burner will continue Yto opcrateV normally under the control of the oven temperature regulator valve until the burner is turnedoff by the main control valve, assuming of course'that the pilot burner'continues to burn. In the vevent of a power failure before gas is turned on by the main control valve, the pilot burner can be manually ignited, as will be hereinafter explained. The supply of gas to both the main burner and the pilot burner will then be controlled by the pilot burner through the thermocouple and safety control valve mechanism as previously described.

In order tc accommodate the apparatus for use in conjunction with any standard type time control mechanism, we provide a supplemental master switch and anormally open solenoid valvl' The supplemental master switch is inserted inthe mainl vcircuit in Vseries with the primary master switch and is adapted to be closed at a 'predetermined time by the time control mechanism. The normally open solenoid valve isiinserted in the branch conduit between the safety ycontrol valve mechanism and the pilot burner, and'is adapted to be closed at a predetermined set time by the time control mechanism. In use Vthe time control mechanism is setto initiate operation of the oven burner at a pref-l determined time and to terminate operation thereof at a predetermined later time, after the main control valve has been turned on which also closes the primary master switch. Then when the supplemental switch which is in series withA the primary switch isV closed by the time control mechanism the apparatus will function in the same manner as previously described, until the time control mechanism effects the closing of the normally open solenoid valve which cuts off the supply of gas to and extinguishes the pilot burner which in turn causesV the safety control valve mechanism to operate to cut off the supply of gas to and thus extinguish the main burner. switch closed is provided in order that the apparatus may be used independently of the time control mechanism when desired.

The principal object of the invention is to provide an improved electrically operated safety control Valve mechanism for use in automatic electric ignition and control systems for gas ranges.

Another object of the invention is to provide a valve mechanism of this character which is very eicient in operation and yet is of very Means to lock the supplemental the main 'oven burner;

simple construction and which can be easily and inexpensively manufactured.

Other and more limited objects of the inven-s tion will be apparent from the following 'specification and the accompanying drawings forming a part thereof in which:

Fig. 1 is a diagrammatic layout showing our improved safety control valve mechanism incorporated in an automatic electric ignition and control system for the oven burner in a cooking range;

Fig. 2 is an enlarged central longitudinal vertical section through the safety control valve mechanism showing the various parts in the positions they assume when the oven burner is turned off;

Fig. 3 is a view similar to Fig. 2 showing the various parts in the positions they are automatically moved to when the main control valve is first turnedon to initiate the operation of Fig. 4 is a horizontal section taken 0n the line 4--4 of Fig. 2;

Fig. 5 is a horizontal section taken on the line 5-5 of'Fig. 2, and

Fig. V6 is a wiring diagram of the system as used in conjunction with a time control mechanism. A

' Referring now to the drawings by reference characters, the numeral IJ indicates a gaseous fuel burner which is mounted 'in or in heating relation to a cooking -range'oven '2. Gaseo'u's'fuel is supplied to the burner I from a manifold M through a'condu'it 3; Interposed in the conduit 3 are a main control va1ve",'our improved safety control valve mechanism generally vindicatediby'f. the numeral 5, and an oven temperature control valve E." The main control valve Itis a cut-off valve of standard 'construction which when in open or on position permits the Vflow of` gas through the conduit 3 from the'inanifold to the burnerI, and in closed roffposition cuts off' the flow of gas to the burnerI I. vThis valve is manually opened and closed byy a handle 'l andv a valve stem t, and directly controls the'operal-Y tion of thee'ntire'system in that it"initiates thel operation of the entiresystem when it is turned to the on position andV terminates the operation whenv it is 'turned'to the od position. From the main control valve d gas, fl'ws thrcugh a conneci' tor 9 to the safety control valve; mechanism 5, to be described in detail"hereinafter.Y From Ytl'ie safety control valve mechanism 5 the gas Yflows through a connector I6, the oven temperature` control valve $3v and the conduit 3. to the burner I.l The'oven temperature control valve Bvfis operative to regulate the amount of gas flowing tothe burner I in order to maintain the oven at any. desired set vtemperature. V The valve S is setto any desired temperature by a handle II having. a pointer I2 which cooperatesA with a graduated dial I3 carried by the valve 6. "The valvey Emis'v controlled according to the temperature settingf by a thermostatic, element |44 which is mounted in the oven 2 and isA connected to the valve Sas' shown at I5. The oven temperatureH control valve 6 is of standard Vwell known "construction, Consequently it is not showny in detail herein.' There are Vmany differentconstructions available, anyone Vof which will work equally'well herein. Gas is also supplied to a'pilot burner vIE5. through a branch conduit I'Iv which extends between the safety control vvalve mechanism and the pilot burner It. A normallyopenv solenoid valve V. which is. adapted. te. be Closed brv` its Splenoid S.

is interposed inthe branch ...conduit |.1 between the safety control'valvei mechanism 5 andthe pilot burner I6 for a purpose to be hereinafter described. 'Ihe solenoid valve V is of standard well known construction. Consequently it is not shown in detail herein. The pilot burner I6 is disposed adjacent the rear end of the main burner i in position to ignite the burner when gas is supplied thereto. An electrical ignition element i8 is operatively associated with the pilot burner i6 in position 4to ignite the pilot burner I6 when gas is supplied thereto. A thermostatic element |9 and. a thermocouple 26 are mounted in position to be heated by a flamefrom the pilot burner. The thermostatic. element i9 .is operative to open and close a switch 2| which controls the energization of the electrical ignition element I3 and a solenoid 22 which` when energized operates the safety control valve mechanism to supply gas to the pilot burner I6, as will be described in connection with the description of the safety control valve mechanism and the operation of the whole apparatus. The thermocouple 26 when heated is operative to hold the safety control valve mechanism in condition to maintain the supply of gas to both the pilot burner I6 and the main burner l, as will also be described in connection with the description of the safety control valve Vmechanism and the operation of the apparatus. A master switch 23 which is associated with the main control valve 4 is adapted to be opened and closed simultaneously with the closing and opening of the main control valve 4. As the control valve 4 is turned from the oif or closed position to the on or opened position the switch 23 is moved from the open position to the closed position by an operating lever 24 which cooperates with a cam section 25 on the main control valve stem 8. Conversely, when the main control valve 4 is turned from the open or on position to the closed or off position the switch 23 is moved from the closed position to the open position. An electric circuit between the thermocouple 26 and the safety control valve mechanism 5 is established by a copper tube 26 which encloses an insulated wire 21. The ignition and control system just described per se constitutes no part of the subject matter of this application but is claimed in our co-pending applications Serial Nos. 153,664 and 163,764, filed April 3, 1950, and May 23,1950, respectively.

The construction of the safety control valvel mechanism 5 which constitutes the subject matter of this application will now be described, reference being had to Figs. 2 to 5 of the drawings. This mechanism comprises two opposed cup shaped casings 36 and 3| having outwardly eX'- tending complementary annular flanges 32 and 33 around the open ends thereof. A partition 34 is clamped between the oasings 36 and 3| by bolts 35 which extend through aligned apertures in the flanges 32 and 33 and the Ypartition 34. Gaskets 36 are interposed between the partition 34 and the flanges 32 and 33 to insure gas tightness. The upper casing 30 has a transverse partition 31 formed integral therewith which provides two chambers 33 and 39 in the upper casing. A single chamber 46 is provided in the lower casing 3|. Communication between the chambers 38 and 40 is established by a passagewayV 4| in the partition 34, and between the chambers 39 and 46 by a passageway 42 in the partition 34.V The passageway 4I is adapted to be closed by a valve 43 which seats in a valve 61" seat44 around the upperaendfofthe passageway 4|,..and the passageway' 42 is'adapted to be closed by a Valve 45 which seats in a valve seat 46 around `the upper endof the passageway 42. The valve 43 is guided inits movement by a valve stem41 which is secured thereto'and is slidably mounted in aligned bores inaisleeve 48 and a boss 49 within the chamber4ll.` The sleeve 43 is held in axial alignmentiwiththe passageway 4| `by a spider 56 secured Vto the underside of the partition 34, and the. boss 49 is formed integral with the bottom wall ofthe casing 3 I. The valve 45 is'guided in its vmovement by a Valve stem 5| which is secured thereto and is slidably mounted in aligned bores inia vsleeve 52 and a boss 53V within the chamber'40. The sleeve 52 is held in axial alignnientwith` the passageway 42 by a spider 54 secured to the underside of the partition 34, and the boss 53 isformed integral with the bottom .wallof the: casing 3l. Vent holes 55 are provided to preventI gas being trapped under the valve stems 41 and 5|. The valve 43 is adapted tol be raised from its seat 44 to open the passageway 4|, and the valve 45 is adapted to be simultaneouslylowered to its seat 46 to close the passageway 42 by a lever 56 which is pivoted at 51 between ears 58 on the lower ends of a stud 59 which is formed integrally with andA extends down into thechamber 40 from the underside of the partitionV 34. lOne. end of the lever 56 is bifurcated as indicated at 60 and straddles the valve stem 41. 'Ihe stem 41 is connected to the lever 56 by a pin 6| which is carried by the bifurcated end 66,0f the lever 56 and extends through an elongated slot 62 in the valve stem 41. The valve stem 5| extends through an elongated aperture 63 ina widened section of the lever 56 and is connected to the lever 56 by a pin 64. The other end of the lever 56 is bifurcated as indicated at 65 and straddles the upper end of the core 66 of the solenoid 22. The lever 55` is connected to the upper end of the core 66 by a pin 68. The solenoid 22 which is secured to the upper side of the bottom wall of the casing 3| byvany suitable means 69, will when energized 'shift the valves 43' and 45 from the position shown in Fig. 2 to the position shown in Fig. 3. A spring 13 disposed about the core 66 beneath a disc 1| carried by the core 66 is operative when the solenoid 22 is de-energized to return the lever 56 and valve 45 back from the position shown in Fig. 3 to the position shown in Fig. 2. The apertures in the lever 56 through which the pins'SI, 64 and 68 extend are slightly elongated as indicated at 6l' in order to prevent any binding when the lever 56 is rocked. An electromagnet 12 is secured to the inner end of a threaded hollow stud 13 within the chamber 36. The stud 13 extends out through an aperture, in the top wall of the casing 3|), which is in axial alignment with the valve 42. The stud 13 and the electromagnet 12 are held in placeby a nut 14. The legs. of the electromagnet 12 have a winding 15 there-l on, one end of whichis connected to the tube 26v and the other end of which is connected to the wire 21 within the tube 26. The tube 26 is inserted into the hollow stud v'|3 and is held in place by a screw fitting Y16. A port 'I9 in the casing 36 provides communication between the chamber 33 and the connector 9 to allow gas to flow from the main control valve 4 through the connector 9 and into the chamber 38. During normal operation of the main; burner gas flows from the chamber 38 through the passageway 4| kinto thechamber yand"frgmjithechamber 40..

through. the passageway 42. into. the/chamber 3.9i..V A port 8.0; which establishes communication be tween. the conduitv Il and the chamber 40 is provided; tosupply; gas tof the. pilot burner I6; and a port 8I establishes communication between the. chamber 39. andI theA connector IU to permit the flow of gas. from the chamber 3S. to the; mainburner- I. through theY oven temperature controlv valve; 6 andi the conduit. 3..

The. master control. switch 23 comprises the4 contacts 82. and; 83.` which are adapted to bebridgedfv by the conductor bar 84; and the switch 2.I comprises.threeicontactsy 89 and 90, which are adaptedi to bebridged; by a. conductor bar 9|I when. the switchl is: in its.l normal closed position;

The supplemental master switch 92, whichl is shown-ingFig comprises `-the' contacts 93` and 94' which area-dapted tobebridgedby aV conductorban 9.5,; anda. switch.96-which is shown in Fig. 6-

comprises. the.. contacts. 91 and 98 which are adapted; tol bef. bridged.I by ay conductor barv 99.--

'Ihecontactel of theswitch 96 is connectedto the side. I ofzthexlinerbyleads IBI and |02, and

the contact ioifthe. switch 36 is connectedtoone end g off the; winding s Illtrof4 the solenoid S-4 by a, lead IM; The other'endofv the winding |53 o frthe solenoid S iseconnectedto therother side I05iof=the line .byfleadsi I 'and I 0l'. The switch gxthus-.controlsethe energization of the solenoid' S which when'.` energized. closes the normallyopen valve. V.. Theigconductor bars 95 and l'SSware mounted. Ona base. IGR; of.V insulating material, which isiadapted `tozhe moved toward andaway from zthe contacts .93; 94, 91 f'and SS'at predeteremined timesby a time control mechanism Iii-9v throughfza.connectingzlinki` I I0. When it is desired to. operate the oven :burner independently herein-.1

The .operationot the; apparatus independently of the time-controlmechanism will' now be Ade-Y To initiatethe operation of 'the .oven;..burner I it is only'necesA v sary3to. set the. ovenv temperature control valve Iiik scribednin .connection `with Fig. 6.

to the desired temperature andA to manually turn the maincontrol'valve 4.fromthe oiv position tothe on position. Afterfthat the ignition andoperation of thehurner are `automatically con-- trolled Yuntil the operation of the burner is iter minated by manually'turning. the main controlvalve 4 from the on positionto the off position. As themain control valve 4is turned lfrom the 01T position to the on: position the master-switch 23 is closed by the. cam:.25."and lever 24. After the main control-valve has been openedfgas canv flow from the manifold through the main con# trol valve 4 and into the chamber. 38 of the safety control valvemechanism 5,"the `various parts of which are in the position shown in'Fig. 2. But the gascan `gono=further since the Valve 43 is s seatedythus closing-the passageway 4i, the only exit from thechamber-38-.fv As soon as the switch 23 is closedcurrentflows from one side IIJO of the line through-the-leadsi I 0 I and I I2 to the terminal 82":and.thencel-through-the conductor bar 84`to.

the terminal.` 83.'1 From ythe terminal 83'thecurj-'- rent owsthroughtheleads I I3 vandi Hl and the There: are many different makes available, any one of which. will work equally well*l V`the magnet 'IZby-the solenoid 22.

ltion element I3 andthe solenoid 22.

8 switch 92 Whichis" lockedinclosed position to the terminali 83 ofL the normally closed switch 2|, and thence through the conductor'barv 9| to the termina-ls. 831 and' 90". From the terminal 83 the current flows through the leadv H5 to the electrical resistance ignition element I8, thence through the ignition element I8'and back to the other side I'5fof the line through the leads I I6 and ID3, thus completing a circuit through the ignition element I which energize-s it and renders` it operable to ignite: the pilot burner I6 as soon as gas is supplied.. thereto. From the terminal 9B of the normally closed switchv 2 I the current ows throughl the` lead lIl'il tothe solenoid 22, thence through the windingoi` the solenoid and back to the other sidel I of the' line through the leadsV I I8 and it,y thus completing al circuit which energizes the solenoid' 2'2. The energization of the solenoid 22 causes it, through the lever 53, to shift the vari ousV parts of the safety lcontrol valve mechanism fromv the position shown in Fig. 2 to the position shown in Fig. 3. In this position the valve 43'is held-f awayfrom. the valve seatV 4' and is held against the endsr or"- the legs of the magnet l2'. This-allowsg-as to flow romthe chamber 3S into the chamber 40 and'thence through the port S andconduit Il to the pilot burner l5 where it is ignited bythe ignition element I8'.v But the gas cannot' yet flow to the main burner I since the valve 45 Vis being held against the seat 4which eutsfof communication'between the chamber d and -thechamber St. As soon as the pilot burner I6v is ignited it. projects a flame against `and heats both thethermocouple 23 and the thermostatic element Iii. The heating ofthe thermocouple 20' generates a minute current which energizes the electromagnet 'IE-suiciently-for it to hold the valve 43 in the vposition shown in Fig. 3,' after the valve 43, has been'moved into engagement with But the magnetvlzf-'when energized by thefthermocouple 20 is not-:strong enough to attract and withdraw-the valve .431 from the position shown in Fig. 2 to the position shown in Fig. 3. 1t can only hold it in this position after it hasbeen moved thereto by the solenoid 22` through the medium of thelever 55. The electricA circuit between the thermocouple 2li and the winding -of the Ymagnet "l2 is through the copper tuber25 and the wire 2'?. This circuit will be maintained `aslong as the thermocouple is heated. After the thermostatic element I9 has been heated suiciently, which is after the thermocouple has energized the electromagnet l2, it will ope-n the normally closed switch 2 I breaking .the circuit to and cie-energizing both the igni- After the pilot 'burner hasbeen ignited there is Vno further need to maintain the ignition element energized. As soon as the solenoid 22 visole-energized the springr'IIlfwill return the lever- 55v and valve 45 backffromithe position shown in Fig; 3 to the position shown in Fig. 2. The valve 43 will be held inthe position shown in Fig. 3 by the electrocation ,is then established between the chambers 38 and 39. through the chamber 40. Gas will then flow from. thechar'nber 38 into the chamber t0 and lthen into the chamber 39. From the chamber 39jgas Vwill flow through the oven temperature control valve 6 and conduit 3 to the main burner I where it will be ignited bythe pilot burner i6. The apparatus is now operating normali and in the'absencev of Jany abnormal YconditionsY it will continue to do so, provided the pilot burner remains ignited; untilthe supply of gas to both the this purpose.

manual closing of the main control valve 4.

In the event the pilot burner I6 is extinguished for any reason during operation, the thermocouple 2i! will cool in a few seconds and deenergize the magnet 12. The de-energization of the magnet l2 will release the valve 43 which will then drop back into engagement with the valve seat 44, as shown in Fig. 2, which will cut H the iiow of gas from the chamber 3B into the chambers 4B and 39, and from them to the pilot light I6 of the main burner I. The burner l will then be extinguishedr along with the pilot burner. As soon as the thermostatic element ie cools it will close the switch 2l which will energize both the ignition element I8 and the solenoid 22 as previously described since the main -control valve 4 is still open and the switch 23 is closed. The

' pilot burner Ilwill then be re-ignitedand the rest of the apparatus will again' function as de-A Y scribed, 'provided there is gas available.

continue to operate normally until terminated by the manual closing of the main control valve, provided of course that all other conditions are normal. In order to operate the apparatus during a-prolonged power failure which occurred prior to operation, it is only necessary to hold a match to the pilot burner I3 and manually move the lever 56 fromthe position shown in Fig. 2

to the position shown in Fig. 3 and hold it in this position a suicient time for the thermocouple 28 to become heated. A pull rod and button l2 and IZI connected to the lower end of the. core 66 of the solenoid22 are provided for After the thermocouple has been heatedthe pull rod |21) may be released 'after which the spring 'lil will return the lever 55 and valve 45 to their initial positions as shown in Fig. 2. The apparatus will then continue to function normally as described under the contr-0l of the pilot burner it and the oven temperature control valve 5. 1

-When the apparatus is used in conjunction with the time control mechanism |09 the time control v.mechanism is set to initiate operation of the main burner i at a predetermined time'and to terminate operation thereof at a predetermined later .time 'The settingof the time control mechanism 199' opens the switches 92 and 96 as shown in Fig. 5. Operating current iis supplied to the time control mechanism from the line lim-H35 by the leads' ill and iBS. After the time control mechanism has been set the main controlvalve 4 is 'manually opened which closes the master switch 23. Then at the Vpredetermined settime the time control mechanism will close the supplemental switch s2 and establish the circuits to the ignition element la and the solenoid 22. The apparatus will then operate as previously described until the pilot burner and the main burner is cut off by the Y timel control mechanism terminates operation by extinguishes thepilot burnerifi. After the pilot.

burner iSv-hasY beenextinguished#the thermoi cools which d eenergizes theelectroit.. .gesaietrfc tro-loewe mechanism ously descrlbedgto cut The mais control valve 4 can then be manually closed at any time.

From the foregoing it will be apparent to those skilled in this art that we have provided a very simple and eicient means for accomplishing the objects of our invention; and it is to be understood that we are not limited to the specific constructions shown and described herein as various modiiications may be made thereto within the scope of the appended claims.

What is claimed isz' 1.- In a device of the character described, the combination of a cup shaped upper casing having a transverse wall intermediate the ends thereof, an opposing cup shaped lower casing, a partition bolted between said upper and said lower casings, said upper casing and said partition defining a rst chamber and a third chamber and said lower casing and said partition'dening a second chamber, a gas inlet port into said first chamber vand agas outlet port from each of said second and said'third chambers, a rst passageway andra second passageway through Vsaid partition, said iirst passageway extending between said rst chamber and said second chamber and said second passageway extending between said second chamber and said third chamber, a firstV valve and a second valve, said rst valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a solenoid secured to the outer face of the bottom wall of said lower casing, and operative connections between said solenoid and said valves through which said solenoid when energized simultaneously shifts said valves to opensaid rst passageway and to close said second passageway.

2. In a device of the character described, the combination of a cup shaped upper casing having a transverse wall intermediate the ends thereof, an opposing cup shaped lower casingy a partition bolted between said upper and said lower casings, said Vupper casing and said partition dening a rst chamber and a third chamber and said lower casing and said partition dening a second chamber, a gas inlet port into said rst chamber and a gas outlet port from each of said second and said vthird chambers, a rst passageway and a second passageway through said partition, Said rst passageway extending between 'said i-lrst chamber and said second chamber and said secvond passageway exten-ding between sai-d second chamber and said third chamber, a iirst valve and a second valve, said first valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a solenoid'secured to the outer face of the bottom wall of said lower casing, operative connections between said solenoid and said valves through which said solenoid when energized simultaneously shifts said valves to open said iirst passageway and to close said second passageway, and meansoperative to hold said first valve rin open position and to return said second valve to open position after said solenoid has been de'energized.

3. In a device of the character described, the combination of a cup shaped upper casing having a'transverserwall intermediate the ends thereof, Yan opposing cup shaped lower casing, a partition vbolted'between"said upperfand said lower casings, .said upper casing and'saidpartition definingf'a g t .,fi'rs"t chamberV and; a third chamber andsaid'lbwer @P1519 eel-statesman 'humain thus; sig'ahd Sallbaiiiininina Slidaterminatin'gthe operation thereof. i i

ber, a gas inlet Yport into Saidiirs't chamber and a .gas outlet port from each of said second and said third chambers, a iirst passageway and a second passageway through said partition, said first passageway extending between said rst chamber and said second chamber and said seoond passageway extending between said secon-d chamber and said thir-d chamber, a first valve and a second Valve, said rst valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a solenoid secured to the outer face of the bottom wall of said lower casing, operative connections between said solenoid and said valves through which said solenoid when energized simultaneously shifts said Valves to open said rst passageway and to close said second passageway, and an electromagnet in said first chamber operative when energized to hold said iirst valve in shifted position after said solenoid has been de-energized.

4. In a device of the character described, the combination of a cup shaped upper casing having a transverse wall intermediate the ends thereof, an opposing cup shaped lower casing, a partition bolted between said upper and said lower casings, said upper casing and said partition deiining a rst chamber and a third chamber and said lower casing and said partition deiining a second charnber, a gas inlet port into said first chamber and a gas outlet port from each of said second and said third chambers, a iirst passageway and a second passageway through said partition, said first passageway extending between said first chamber and said second chamber and said second passageway extending between said second chamber and said third chamber, a rst valve and a second valve, said rst valve being operative to open and close said rst passageway and said second valve being operative to open `and close said second passageway, a solenoid secured 4 to the outer face of the bottom wall Aof said lower casing, operative connections between said solenoid and said valves through which saidsolenoid when energized simultaneously shifts vsaid valves to open said first passageway and to close said second passageway, and means in said second chamber operative to shift said second valve back to open position after said solenoid has been deenergized.

5. In 'a device of the character described, the combination of a cup shaped upper casing having a transverse wall intermediate the ends theroi, an opposing cup shaped lower casing, a, partition bolted between said upperfand said lower` casings, said upper casing and saidpartition defining a first chamber and a third chamber and said lower casing and said partition dening a second chamber, a gas inlet port into said iirst chamber and a gas outlet port from each 'of said second and said third chambers, a iirst Vpassageway and a second passageway through said partition, said rst passageway extending between said 'first chamber and said second vchamber and said second passageway extending between said second chamber and said third chamber, a rst valve and a second valve, said 'first valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a solenoid secured to the outer face of the bottom wall/of said lower casing, operative connections between said solenoid and said valves through which said solenoid when energized 'simultaneously shifts said valves to open lsaid rst passageway and to close said second passageway, an electromagnet in said first "12 chamber operative when energized to hold said first valve in open position after said solenoid has been de-energized, and spring means in said second chamber operative to shift said second valve back to open position after said solenoid has been de-energized.

6. In a device of the character described, the combination of a cup shaped upper casing having a transverse wall intermediate the ends thereof, an opposing cup shaped lower casing, a partition bolted between said upper and said lower casings, said upper casing and said partition defining a iirst chamber and a third chamber and said lower casing and said partition defining a second chamber, a gas inlet port into said hrst chamber and a gas outlet port from each of said second and said third chambers, a first passageway and a second passageway through said partition, said rst passageway extending between said iirst chamber and said second chamber and said second passageway extending between said second chamber and said third chamber, va first valve and a -second valve, said first valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a pivoted lever in said second chamber pivotally connected to each or" said Valves, and a solenoid secured to the outer surface of the bottom wall of said lower casing connected to said lever and operative when energized to rock said lever to simultaneously shift said valves to open said first passageway and to close said second passageway.

7. In a device of 'the character described, the combination 'of a cup shaped upper casing having a transverse wall intermediate the ends thereof, an opposing 'cup shaped lower casing, a partition bolted between said upper and said lower casings, said upper casing kand'said partition defining a iirst chamber and a third chamber and said lower casing and said partition dening a second chamber, a gas inlet port .into said iirst chamber and a gas outlet port from each of said second and said third chambers, a rst passageway and a second passageway through Vsaid partition, said irst passageway extending between said iirst chamber and said second chamber and said second passageway extending between said second chamber and said third chamber, a first valve and a second Valve, said irst valve being operative to open and close said rst passageway and said second valve being operative to open and close said second passageway, a pivoted lever in said second chamber pivotally connected to each of said valves, va solenoid secured to the outer surface of the bottom wall of said lower casing connected to said lever and operative when energized to rock said lever to simultaneously shift said Valves to open said first passageway and to close said second passageway, an electromagnet in said rst chamber operative when energized to hold said rst valve in open position after said solenoid has been de-energized, and spring means in `said second chamber operative to rock said lever to shift said second valve back to open position upon the dehenergization of said solenoid.

CHARLES M. MAYER. JOHN M. HOFF,

References cited in the nie of this patent UNITED STATES PATENTS Y Date 

